Polyester polymers of 3-hydroxy-4&#39;-(4-hydroxyphenyl)benzophenone or 3,4&#39;-dihydroxybenzophenone and dicarboxylic acids

ABSTRACT

Aromatic polyesters derived from at least 10% glycols of the structure ##STR1## are disclosed. The polyesters have an inherent viscosity of at least 0.5 as measured from a 0.5 g solution in 100 ml of an equal volume mixture of p-chlorophenol and 
     1,2-dichloroethane, and a heat of fusion of less than 1.5 joule per gram.

SUMMARY

This invention relates to polyester polymers of3-hydroxy,4'-(4-hydroxyphenyl)benzophenone or 3,4'-dihydroxybenzophenoneand dicarboxylic acids that are processable in molten phase, and may beprocessed to produce molded articles, fibers and films. Films of thesepolyesters are biaxially orientable, thus yielding products ofsubstantial strength in two dimensions.

BACKGROUND

Melt fabricable polyesters containing at least 85 mole % of3-hydroxy,4'-(4-hydroxyphenyl)benzophenone and at least 85 mole % of thediacid of p-phenylene, 2,6-naphthalene, or p,p'-bi-phenylene, are knownin the art and are described in Irwin U.S. Pat. No. 4,245,082. Filmsprepared from the polyester polymers of Irwin cannot be biaxiallyoriented. U.S. Pat. No. 4,224,433 to Calundann et al. discloses whollyaromatic polyesters in which approximately 15 to 30 mole percent of theunits polymerized may be a mixture of isophthalic acid and terephthalicacid.

DETAILED DESCRIPTION

The polyesters of the present invention contain repeating units ofpolymerized 3-hydroxy,4'-(4-hydroxyphenyl)benzophenone, i.e., ##STR2##or 3,4'-dihydroxybenzophenone, i.e., ##STR3## bonded to repeating unitsof aromatic dicarboxylic acid units, up to 80 mole percent of thearomatic dicarboxylic acid units may be selected from the groupconsisting of terephthalic acid, 2,6-naphthalene dicarboxylic acid;1,4-naphthalene dicarboxylic acid, 1,5-naphthalene dicarboxylic acidparadibenzoic acid, 4,4'-(dicarboxy)diphenyl ether, and2-bis(4-carboxyphenoxy)ethane and from 20 to 100 mole percent of thearomatic dicarboxylic acid units selected from the group consisting ofisophthalic acid, 1,3-naphthalene dicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 1,6-naphthalene dicarboxylic acid and 1,7-naphthalenedicarboxylic acid. Optionally the polymer can contain up to 100 molepercent dicarboxylic acid units of a C-6 to C-16 alkylene dicarboxylicacid. Optionally the polymer can contain up to 300 mole percent based ontotal glycol present of a hydroxy acid selected from the groupsconsisting of p-hydroxybenzoic acid, 6-hydroxy-2-naphthoic acid,4-hydroxy-1-naphthoic acid, 5-hydroxy-1-naphthoic acid,4-hydroxy-2-phenyl benzoic acid and 4-hydroxy-3-phenyl benzoic acid, inwhich case up to 100 mole percent of the dicarboxylic acid present canbe any of those named above. Optionally the polymer can contain up to 80mole percent based on total glycol present of a glycol selected from theclass consisting of hydroquinone, which optionally can be substitutedwith a methyl, dimethyl, ethyl, methoxy, ethoxy, fluoro, chloro orbromo; phenylhydroquinone; (methylphenyl)hydroquinone;4,4'-dihydroxybiphenyl; resorcinol; bisphenol A;2,2-bis(parahydroxyphenyl)hexafluoropropane; di(4-hydroxyphenyl)sulfone;1,4-naphthalene diol; 1,5-naphthalene diol and 2,6-naphthalene diol.

These polyesters can be injection molded, spun into fibers, and formedinto films by extrusion or pressing. The films may be stretched up tofive-fold at temperatures above the glass transition temperature.

The polyesters of this invention have glass transition temperatures inthe range of about 40° to 180° C., and inherent viscosities in the rangeof about 0.4 to 4.0 dl/g as defined by the equation. ##EQU1## wherein(ηrel) represents the relative viscosity and C represents aconcentration of 0.5 gram of the polyester in 100 ml of solvent. Therelative viscosity (ηrel) is determined by dividing the flow time in acapillary viscometer of the dilute solution by the flow time for thepure solvent. Flow times are determined at 25° C., and the solvent is a50/50 volume mixture of p-chlorophenol and 1,2-dichloroethane.

The polymers of the present invention exhibit a heat of fusion (ΔH_(f))of less than 1.5 Joules per gram and preferably 0 Joules per gram,measured as described below. By heat of fusion is meant the energy pergram involved in conversion from the solid crystalline state to theliquid crystalline state. Prolonged exposure to temperatures above theTg of a given polymer of the present invention can cause a crystallinephase to develop which will have a higher ΔH_(f).

As used herein thermal characterization of the polymers is done on a DuPont Thermal Analyzer, Model 1090 equipped with a Du Pont DSC cell. Aknown weight of resin (usually 5 to 10 mg) is sealed in a DSC pan andmaintained under nitrogen throughout the test. The sample is subjectedto a heating cycle to remove any crystallinity, thereby eliminating theeffects of prior thermal history. This cycle consists of heating to 360°C. at 25° C./min. and holding at 360° C. for two minutes.Crystallization under controlled conditions is effected in a cooldowncycle wherein the sample is cooled from 360° to 40° C. at a rate of 30°C./min. and then maintained at 40° C. for five minutes. Thermalcharacterization parameters are taken from the second heat-up cyclewhich consists of heating from 40° C. to 360° C. at 25° C./min. Theglass transition temperature (Tg) is defined as the inflection pointwhere the heat flow--temperature curve changes in slope. Crystallinemelting shows a characteristic endothermic peak where the melting point(Tm) is taken as the tip of the peak. Heat of fusion (ΔH_(f)) isdetermined from the area of the peak relative to a calibration usingindium at 156° C. where ΔH_(f) =28.46 J/g.

Polymers of the class described herein having low values of (ΔH_(f))(i.e., below 1.5 J/g) are stretchable whereas similar polymers derivedfrom 3-hydroxy-4'-(4-hydroxyphenyl)benzophenone or3,4'-dihydroxybenzophenone with high values of (ΔH_(f)) are notstretchable.

The polymers of the present invention exhibit optical anisotropy.Optical anisotropy is an indication that the polymer is in the form ofliquid crystals which results in the polymer being much more readilymelt processable than polymers which are isotropic.

Optical anisotropy of the copolyester melts can be determined bymodification of known procedures. It is well known that opticallyanisotropic materials cause polarized light to be rotated, whereasrotation of polarized light is zero for isotropic materials. Thus,optical anisotropy can be determined by placing a sample of the polymerbetween crossed polarizers on a heating stage of a polarizing microscopeand bringing the temperature up to and beyond the polymer flowtemperature. If the polymer is optically anisotropic in the melt, abright field will be observed at temperatures above the polymer flowtemperature. This may be confirmed through use of the thermooptical test(TOT) which is described in U.S. Pat. No. 4,118,372. Polymers which passthis test are considered to be optically anisotropic. The apparatus issimilar to that described by I. Kirshenbaum, R. B. Isaacson, and W. C.Feist, Polymer Letters, 2, 897-901 (1964).

The polyesters are prepared by combining substantially equal molaramounts of glycols and diacids. The glycols may be added in the form ofdiesters such as the diacetates. Alternatively the free glycol can bereacted with a dichloride of the diacid, the free acid, or estersthereof. The mixture is heated in a reaction vessel under an inertatmosphere with stirring for about 1 to 3 hours, at a temperature abovethe melting points of the reactants. A vacuum is usually applied duringthe course of the reaction to remove volatile by-product such as aceticacid.

The polymers of the present invention are useful as films which can besubjected to high temperatures.

The polyester may be spun into filament by the conventional meltspinning techniques.

The polymers of the present invention can be molded and spun into fibersin addition to being made into biaxially orientable films.

Uni- and Biaxial Stretching of Extruded or Molded Sheets

A sheet of polymer, 5 to 20 mils thick, is prepared either by extrusionthrough a slit die at about 300° C., or by compression molding betweentwo plates at 320° C. for 30 seconds in a hydraulic press.

For biaxial stretching, square samples, either two or four inches on aside, cut from the sheets are mounted in a pantograph preheated to 20°C. to 80° C. above the glass transition temperatures (Tg) of thepolymers (i.e. 60° to 200° C.). After thermal equilibration for 0.2 to 3minutes, the samples are stretched either simultaneously or sequentiallyin the X and Y directions at rates between 100 and 20,000% per minute. Apolymer is considered to be a film former if it stretchs more than 50%at a draw rate of 100%/min. after a three minute warmup period, withoutbreaking.

For uniaxial stretching, strips 0.5 in. wide by 1.5 to 3 in. long cutfrom the polymer sheets are mounted in the jaws of a tensile testerwhich is inside a heated compartment maintained at 80° to 190° C. Aftera heatup time of 0.2 to 3 minutes, the samples are elongated at a rateof 20% to 500% per minute.

Physical Testing

Tensile properties were measured with an Instron machine using aconstant head speed of 0.05 cm/mn at 25° C., relative humidity of 50%,and a grip distance of 2.5 cm. The modulus reported in the initialYoung's modulus derived from a stress-strain curve determined without anextensiometer. Strength is the strength at break. The elongation is alsothe elongation at break. Whenever the sample does not break, thesign >is used.

In some cases in the Examples the units reported have beenmathematically converted from the units originally recorded.

EXAMPLE 1 Preparation of 3-hydroxy,4'(4-hydroxy-phenyl)benzophenonediacetate

One hundred seventy grams (1 mole) of p-phenylphenol, 138 grams (1 mole)of 3-hydroxybenzoic acid, 400 mL of hydrogen fluoride (HF), and 170grams of boron trifluoride were reacted for 15 hours at 0° C. underautogenous pressure in an autoclave. Then the contents were mixed inexcess water/ice to precipitate a green solid. After filtering andwashing with water to remove the remaining HF, the powder was slurriedwith water, neutralized with 80 grams sodium bicarbonate (NaHCO₃) untilpH=8, filtered, and washed with water. After drying at 25° C. in air for10 hours, the solid was dissolved in 3000 ml ethyl acetate, stirredovernight, and precipitated in a blender with 6000 ml n-hexane byvolume. The solid was separated by filtration, washed two times withn-hexane, and dried at 120° C. under vacuum. The product was 160 gramsof a beige crystalline solid which was determined by NMR analysis to bethe 3-hydroxy,4'(4 -hydroxyphenyl)-benzophenone. This solid wasacetylated directly by refluxing 3 hours with 640 ml of acetic anhydrideand one drop of concentrated sulfuric acid. The solution was cooled to25° C. and allowed to stand overnight. The solid was filtered, washedwith methanol, and dried at 90° C. under vacuum. The product was 150grams of 100% pure 3-hydroxy, 4'-(4-hydroxyphenyl)benzophenone diacetateas determined by NMR analysis. Its melting point was 120°-121° C.

Polymerization

One hundred eighty-seven grams (0.5 mole) of3-hydroxy,4'(4-hydroxyphenyl)benzophenone diacetate and 91.5 grams(0.525 mole) of suberic acid (HOOC(CH₂)₆ COOH) are simultaneouslyintroduced into a glass polycondensation reactor fitted with amechanical stirrer, nitrogen inlet, vacuum outlet, and a refluxcondenser. After purging, the reactor is heated with a Wood's metal bathset at 140° C. while vacuum is applied for 15 minutes. Then undernitrogen the contents are heated at atmospheric pressure to 235° C.where acidolysis begins. After one hour, the temperature is raised to250° C. and maintained there until 78% of the theoretical volume ofacetic acid distills over. The pressure is then gradually reduced to 5KPa over a period of 1 hour and 20 minutes and then it is furtherreduced to 0.04 KPa. The reactor is maintained at 260° C. for 4 hoursuntil the desired viscosity is obtained. The product had 200 grams ofpolymer having a structure as determined by NMR analysis consisting ofperfectly alternating carbonyl hexamethylene carbonyl andoxy-3-benzoyl-4-phenyl-4-phenoxy units. The inherent viscosity was 0.87dlg⁻¹. The polyester had a Tg of 60° C. and a liquid crystallineanisotropic-isotropic transition of 170° C.; that is, the anisotropy ofthe polyester melt under crossed polarized light fades at 170° C. Thepolyester had no solid crystalline to liquid crystalline transition(ΔH_(f) of 0 Joules per g). The polyester has dead bend properties.

EXAMPLE 2

A polyester prepared similarly to that of Example 1 was extruded as afilm. Dimensions of the sample were 8.1×76 mm. Thickness was variable.The film was uniaxially stretched in the machine direction while heatwas applied with the following conditions of temperature, elongation,speed, and drawing ratio. Results are as follows:

    ______________________________________                                        Thick-                                                                              Temp-   Drawing  El.   Mod-                                             ness  erature Ratio    Speed ulus  Strength                                                                             El. at                              (mm)  °C.                                                                            %        cm/mn MPa   MPa    Break-%                             ______________________________________                                        0.06  106     285      10    12930 207    12                                  0.09  106     200      20    9655  207    12                                  0.11   96     200      20    8414  228    18                                  ______________________________________                                    

EXAMPLE 3

The polyester was the same as Example 1. It was compression molded at190° C. with a thickness of 0.5 mm. The sheet was cut into dimensions50×50 mm and biaxially stretched at 80° C. to 400% with a stretchingspeed of 200 cm/min.

The resulting film was shiny, tough, and had the following balancedproperties:

Tensile Modulus MPa: 4138,

Tensile Strength MPa: 145,

Elongation At Break % 14.

EXAMPLE 4

Eighteen grams (0.048 mole) of 3-hydroxy,4'(4-hydroxyphenyl)benzophenonediacetate and 11.6 grams (0.05 mole) of 1,10-decanedicarboxylic acidwere simultaneously introduced into a glass polycondensation reactorfitted with a mechanical stirrer, nitrogen inlet, vacuum outlet, and areflux condenser. After purging, the reactor was heated to 190° C. for20 minutes; then the temperature was raised to 265° C. where the aceticacid began to distill. After 55 minutes, 80% of the theoretical volumeof acetic acid distilled over. The pressure was gradually reduced to 5KPa for 10 minutes and then further reduced to 0.07 KPa for 20 minutesat 280° C. The yield of polymer was 90% of theoretical. The inherentviscosity was 1.23 dlg⁻¹. The polyester had a Tg of 48° C. and a liquidcrystalline anisotropic-isotropic transition at 135° C.; that is, theanisotropy of the polyester melt under crossed polarized light faded at135° C. There was no solid crystalline to liquid crystalline transition,i.e., ΔH_(f) =0 Joules per gram. The polyester was analyzed by NMR toconsist of perfectly alternating carbonyl andoxy-3-benzoyl-4-phenyl-4-phenoxy units. Films of the polyester werecompression molded at 175° C. to provide test specimens havingdimensions of 0.3×2×21.5 mm. Results were as follows:

Tensile Modulus MPa: 566,

Tensile Strength MPa: 41,

Elongation At Break %: 77.

The above polyester test specimen was cold drawn 120% with newdimensions of 0.2×1.78×23.4 mm. Results are as follows:

Tensile Modulus MPa: 1800,

Tensile Strength MPa: 72,

Elongation At Break %: 30.

EXAMPLE 5

A polyester prepared as in Example 4 was compression molded into a sheetand cut into a square shape 50×50 mm. It was biaxially stretched 100% at60° C. Results are as follows:

Tensile Modulus MPa: 2000,

Tensile Strength MPa: 110,

Elongation At Break %: 22.

EXAMPLE 6

561 g (1.5 mole) of 3-hydroxy,4'-(4-hydroxyphenyl)benzophenonediacetate, 150 g (0.9 mole) of terephthalic acid and 100 g (0.6 mole) ofisophthalic acid were simultaneously introduced into a glasspolycondensation reactor similar to Example 1. After purging the reactorwas heated using a Wood's metal bath at from 185° C. to 300° C. for 1hr. 15 min. then to 330° C. for 1 hr. 160 cc of acetic acid wascollected. The nitrogen is blown in for 30 mn. The temperature wasdecreased to 290° C. The pressure was gradually reduced to 5 KPa for 35min. and then further reduced to 0.01 KPa for 1 hr 10 min. at 300° C.,for 15 min. at 320° C. and for 1 hr 30 min. at 330° C. The pressure wasthen decreased to 0.009 KPa for 1 hr 15 min. The yield of the polymerwas 94% of theoretical. The inherent viscosity was 1.2 dlg⁻¹. Thepolyester has a Tg of 132° C., a liquid crystalline phase up to >350° C.and a ΔH_(f) of 0 J/g.

The polymer was melted in an extruder at 330° C. and extruded through a20 cm lip die at 300° C. to produce a film with a thickness of 0.1 to0.18 mm. The extruded film was quenched on a cooled casting drum to givea smooth film.

The film was then cut into a 5×5 cm sheet which was uniaxially andbiaxially stretched at 185° C. to give a smooth shiny and thin (25 to 50μm thick) film. Strips were cut from these films in the extruded(machine direction) and 90° of the extruded (transverse direction) film.Tensile properties from nonheat-treated samples were:

    ______________________________________                                               Machine Direction                                                                           Transverse Direction                                     Stretching                                                                             Mod-                  Mod-                                           Ratio    ulus    Strength E-   ulus  Strength                                                                             E-                                MD   TD      Kpsi    Kpsi   long Kpsi  Kpsi   long                            (%)  (%)     (MPa)   (MPa)  %    (MPa) (MPa)  %                               ______________________________________                                         0    0       1500    32     5    300   4      2                                           (10300) (220)       (2100)                                                                               (30)                                   0   200      1200    25    25   1100   21    11                                            (8300) (170)       (7600)                                                                              (140)                                  100  200      2400    51    10    800   16    16                                           (16600) (350)       (5500)                                                                              (110)                                  ______________________________________                                    

EXAMPLE 7

112.2 g (0.3 mole) of 3-hydroxy, 4'-(4-hydroxyphenyl)benzophenonediacetate, 39 g (0.8 mole) of 2,6 naphthalene diacid and 20 g (0.12mole) of isophthalic acid were simultaneously introduced into a glasspolycondensation reactor as in Example 1. After purging with nitrogen,the reactor was heated using a Wood's metal bath at from 185° to 310° C.for 1 hr 50 mins. Thirty-one cc of acetic acid was collected. Nitrogenwas blown in for 20 mins. Partial vacuum (5 KPa) was applied for 15 minsand full vacuum (0.03 KPa) for 5 hrs. The yield was 99% (134 g). Theinherent viscosity was 0.8 dlg⁻¹. The glass transition temperature was134° C. as determined by DSC. The polymer had a liquid crystalline phaseup to 350° C. as determined by optical microscopy and a ΔH_(f) of 0 J/g.

A molded film of the polymer was uniaxially stretched 100% at 170° C.

EXAMPLE 8

109.4 g (0.292 mole) of 3-hydroxy, 4'-(4-hydroxyphenyl)benzophenonediacetate, 49.6 g (0.205 mole) of paradibenzoic acid, and 14.6 g (0.088mole) of isophthalic acid were simultaneously introduced into a glasspolycondensation reactor as in Example 1. After purging, the reactor washeated with Wood's metal bath to 300° C. for 2 hrs 25 mins. Partialvacuum (5 KPa) was applied for 15 mins then full vacuum (0.03 KPa) for 3hrs 45 mins at 330° C. The yield of polymer is 92%. The inherentviscosity was 1.5 dlg⁻¹. The glass transition temperature was 133° C. asdetermined by a differential scanning calorimeter (DSC). The polymer hada liquid crystalline phase up to above 350° C. as determined by opticalmicroscopy and a ΔH_(f) of 0 J/g. Compression molded film can bestretched up to 100% at 160° -180° C.

EXAMPLE 9

45 grams (0.12 mole) of 3 hydroxy-4'-(4-hydroxyphenyl)benzophenonediacetate, 65 grams (0.28 mole) of chlorohydroquinone diacetate, 46.5 g.(0.28 mole) of terephthalic acid and 20 g. (0.12 mole) of isophthalicacid were introduced into a glass polycondensation reactor. Afterpurging, with nitrogen, the reactor was heated in a Wood's metal bathfrom 185° to 310° C. for 1 hr. 40 min.--43 ml. of acetic acid wasdistilled. The temperature was increased to 330° C. for 20 min. thennitrogen was blown in for 1 hr. The temperature was then decreased to290° C. for 30 min. Partial vacuum (5 KPa) was applied for 20 min., thenfull vacuum (0.03 KPa) for 15 min. at 290° C. and 2 hrs. 25 min. at 320°C. The yield of polymer was 92% (117 g.). The inherent viscosity was 1.4dlg⁻¹. The Tg was 115° C. as determined by DSC and the ΔH_(f) was 0 J/g.

The polymer was compression molded at 320° C. and then biaxiallystretched at 165° C. at a rate of 500% per minute.

    ______________________________________                                                          Tensile    Tensile                                                                              Elong.                                              %       Modulus    Strength                                                                             Break.                                    Direction Stretch (Kpsi)     (Kpsi) %                                         ______________________________________                                        X         200     2500       37     1.8                                       X         100     1300       17     1.5                                       ______________________________________                                    

EXAMPLE 10

39.3 g. (0.105 mole) of 3 hydroxy-4'-(4-hydroxyphenyl)benzophenonediacetate, 66.2 g. (0.245 mole) of phenylhydroquinone diacetate, 40.7 g.(0.245 mole) of terephthalic acid and 17.4 g. (0.105 mole) ofisophthalic acid were introduced into a glass polycondensation reactor.After purging, with nitrogen, the reactor was heated in a Wood's metalbath from 185° to 310° C. for 2 hr. 45 min. Thirty-four (34) ml. ofacetic acid was collected--then nitrogen was blown in for 1 hour.Partial vacuum was applied for 15 min. and then full vacuum (0.03 KPa)for 3 hr 20 min. at 310° C. The yield was 91% (110 g.). The inherentviscosity was 0.5 dlg⁻¹. The Tg was 146° C. as determined by DSC. TheΔH_(f) was 0 Joules per gram.

The polymer was compression molded at 320° C. and uniaxially stretchedat 160° C. up to 100% (2×). The rate of stretching was 4000%/min.

EXAMPLE 11

Seven and five-tenths grams (0.02 mole) of3-hydroxy-4'(4-hydroxyphenyl)benzophenone diacetate, 3.9 grams (0.02mole) of hydroquinone diacetate, 6 grams (0.036 mole) of terephthalicacid, 0.7 grams (0.004 mole) of isophthalic acid were simultaneouslyintroduced into a 250 ml glass polycondensation reactor fitted with amechanical stirrer, nitrogen inlet, vacuum outlet and a refluxcondenser. After purging with nitrogen, the reactor was heated with aWood's metal bath from 100° C. to 280° C. for 2 hrs., then 1 hr. at 300°C. Nitrogen was blown in for 1/2-1 hr. Partial vacuum (5 KPa) wasapplied for 10 min., then full vacuum (0.03 KPa) for 3 hrs. The yield isalmost quantitative. The composition had an inherent viscosity(I.V.)=2.4 dlg⁻¹, Tg (by DSC) was 118° C., ΔH_(f) =0 J./g, clearingtemperature, Tc °C. (where the systems become isotropic) was greaterthan 350° C.

The polyester was compression molded at 220° C. Samples cut along theflow pattern and uniaxially stretched at 180° C. in a hot box using anInstron machine at the cross head speed of 12.5 mm/min. (0.5"/mm) to the100% extension. The tensile strength thus obtained was 40.9 Kpsi (280MPa).

EXAMPLE 12

One hundred four and seven-tenths grams (0.28 mole) of3-hydroxy-4'(4-hydroxyphenyl)benzophenone diacetate, 23.3 grams (0.12mole) of hydroquinone diacetate, 46.5 grams (0.28 mole) of terephthalicacid, and 20 grams (0.12 mole) of isophthalic acid were simultaneouslyintroduced into a glass polycondensation reactor as Example 1. Afterpurging with nitrogen, the reactor was heated from 180° C. to 300° C.for 3 hrs. Forty-two cc (92%) of theoretical value of acetic acid wascollected. Nitrogen was blown in for 15 mins. Partial vacuum (5 KPa) wasapplied for 15 mins, then full vacuum (0.03 KPa) for 4 hrs 30 mins. Theyield was 94% (138 grams). The inherent viscosity was 1 dlg⁻¹. The Tgwas 131° C. as determined by DSC, ΔH_(f) was 0 J./g. The polymer forms aliquid crystalline phase up to above 350° C. as determined by opticalmicroscope.

The above polymer was compression molded at 200° C. (0.25 mm thick). Asheet of 50×50 mm was cut and biaxially stretched up to 200% in eachdirection to give a smooth film with the following physical properties(nonheat treated):

Stretching Temperature: 150° C.,

Tensile Modulus Kpsi (MPa): 1300 (9,000),

Tensile Strength Kpsi (MPa): 22.4 (150),

Elongation at Break, %: 2.

EXAMPLE 13

36 g (0.2 moles) of p-hydroxybenzoic acid acetate, 74.8 g (0.2 moles) of3-hydroxy-4'-(4-hydroxyphenyl)benzophenone diacetate, 23 g (0.14 moles)of terephthalic acid and 10 g (0.06 moles) of isophthalic acid weresimultaneously introduced into a glass polycondensation reactor fittedwith a mechanical stirrer, nitrogen inlet, vacuum outlet and a refluxcondenser. After purging, the reactor was heated using a Wood's metalbath from 185° C. to 260° C. for 1 hr 30 min. 18 ml of acetic acid whichis 50% of expected amount, was collected. The temperature was increasedto 265° C. for 2 hr 5 min. 28 ml of acetic acid was collected. Thetemperature was increased to 310° C. for 25 min. Nitrogen was blown infor 15 min. Partial vacuum (5 KPa) was applied for 15 min. then fullvacuum (0.03 KPa) for 3 hr at 310° C. The yield of polymer was 91% (98g). The inherent viscosity was 1 dlg⁻¹. The Tg was 116° C. as determinedby DSC. It had no melting point (crystalline-liquid crystallinetransition even after annealing at 220° C. for 74 hr), ΔH_(f) was 0 J/g.

The polyester was compression molded at 320° C. for 1 min. It wasbiaxially stretched at 175° C. to give a smooth and shiny film. Physicalproperties of film (50 μm thick) were:

    ______________________________________                                               X Direction (Tensile)                                                                       Y Direction (Tensile)                                    Stretching                                                                             Mod-                  Mod-                                           Ratio    ulus    Strength E-   ulus  Strength                                                                             E-                                MD   TD      Kpsi    Kpsi   long Kpsi  Kpsi   long                            (%)  (%)     (MPa)   (MPa)  %    (MPa) (MPa)  %                               ______________________________________                                        200  200      460     6     1.6   2100  40    3                                            (3200)  (40)        (14500)                                                                             (280)                                  ______________________________________                                    

EXAMPLE 14

54 g (0.3 moles) of p-hydroxybenzoic acid acetate, 56 g (0.15 moles) of3-hydroxy-4'-(4-hydroxyphenylbenzophenone diacetate, 17.4 g (0.105moles) of terephthalic acid and 7.5 g (0.045 moles) of isophthalic acidwere simultaneously introduced into a reactor identical to that ofExample 1. The reactor was heated from 120° C. to 260° C. for 2 hr 35min. 28 ml of acetic acid was collected. The temperature was increasedto 310° C. for 30 min. Nitrogen was blown in for 40 min. Partial vacuum(5 KPa) was applied for 15 min and full vacuum (0.03 KPa) for 3 hrs at310° C. The yield of polymer was 91% (90 g). The inherent viscosity was1.1 dlg⁻¹. The Tg was 110° C. as determined by DSC. The polymer as madedid not have any crystalline phase, ΔH_(f) was 0 J./g.

The above polyester was compression molded at 320° C. for 1 min. It wasbiaxially stretched at 175° C. to give a smooth and shiny film. Physicalproperties of the film (50 μm or 2 mil thick) were:

    ______________________________________                                               X Direction (Tensile)                                                                       Y Direction (Tensile)                                    Stretching                                                                             Mod-                  Mod-                                           Ratio    ulus    Strength E-   ulus  Strength                                                                             E-                                MD   TD      Kpsi    Kpsi   long Kpsi  Kpsi   long                            (%)  (%)     (MPa)   (MPa)  %    (MPa) (MPa)  %                               ______________________________________                                        100  100      470     8     2.5  1200   14    1.8                                          (3250)  (55)        (8300)                                                                              (100)                                  ______________________________________                                    

EXAMPLE 15

74.8 g (0.2 mole) of 3-hydroxy, 4'(4-hydroxyphenyl)benzophenonediacetate, 32.2 g (0.2 mole) of isophthalic acid and 72 g (0.4 mole) ofp-hydroxybenzoic acid acetate were simultaneously introduced into aglass polycondensation reactor identical to Example 1. After purging,the reactor was heated using a Wood's metal bath from 185° C. to 265° C.for 2 hr. 35 min. 37 cc of acetic acid was collected. Nitrogen was blownin for 40 min. while the temperature was increased to 310° C. Thepressure was gradually reduced to 5 KPa for 10 min. and then furtherreduced 0.07 KPa for 4 hours at 330° C. The yield was 96%. The inherentviscosity was 0.7 dlg⁻¹. The polyester had a Tg of 131° C. and a liquidcrystalline phase up to 350° C., and a ΔH_(f) of 0 J/g.

The above polyester was compression molded at 320° C. for 1 min. It wasbiaxially stretched at 185° C. to give a smooth and shiny film. Physicalproperties of a nonheat-treated film (25 μm or 1 mil) were:

    ______________________________________                                               X Direction (Tensile)                                                                       Y Direction (Tensile)                                    Stretching                                                                             Mod-                  Mod-                                           Ratio    ulus    Strength E-   ulus  Strength                                                                             E-                                MD   TD      Kpsi    Kpsi   long Kpsi  Kpsi   long                            (%)  (%)     (MPa)   (MPa)  %    (MPa) (MPa)  %                               ______________________________________                                        100  100      900     20    7.5  1100   23    6.3                                          (6200)  (140)       (7600)                                                                              (160)                                  200  200     1300     50    6    1400   30    7                                            (9000)  (340)       (9700)                                                                              (210)                                  ______________________________________                                    

EXAMPLE 16 Preparation of 3,4'-Dihydroxybenzophenone Diacetate

Ninety-four grams (1 mole) of phenol, 138 grams (1 mole) of3-hydroxybenzoic acid, 400 ml of hydrogen fluoride (HF), and 170 gramsof boron trifluoride were allowed to react for 15 hours at 0° C. underautogeneous pressure in an autoclave. Then the reactor contents weremixed in excess water/ice. After filtering and washing the resultinggreen solid with water to remove the remaining HF, the powder wasslurried with water, neutralized with sodium bicarbonate (NaHCO₃)solution until pH=8, filtered and finally washed with water. Afterdrying at 25° C. in air for 10 hours and under vacuum at 120° C. for 12hours, there was obtained 160 grams of a beige, crystalline solid whichwas determined by NMR analysis to be 3,4'-dihydroxybenzophenone. Thesolid was acetylated directly by refluxing 3 hours with 640 ml of aceticanhydride and one drop of concentrated sulfuric acid. The solution wasadded to ice/water. The resultant solid was filtered, washed with coldmethanol, and dried at 60° C. under vacuum. There was obtained 150 gramsof pure 3,4'-dihydroxybenzophenone diacetate as determined by NMRanalysis. Its melting point was 83°-84° C.

Polymerization

Twelve grams (0.04 mole) of 3,4'-dihydroxybenzophenone diacetate, 4.6grams (0.028 mole) of terephthalic acid and 2 grams (0.012 mole) ofisophthalic acid were introduced into a glass polycondensation reactor.After purging with nitrogen, the reactor was heated in a Wood's metalbath from 185° C. to 300° C. over a 90 minute period. Then nitrogen wasblown in for 10 minutes as a sweep. Partial vacuum (5 KPa) was appliedfor 15 mins., then full vacuum (0.03 KPa) for 5 hrs. 30 min. at 300° C.The yield of polymer was 80% (11 g). The inherent viscosity was 1.1dlg⁻¹. The Tg was 127° C. as determined by DSC, ΔH_(f) was 0 J/g.

A polymer sheet was compression molded at 260° C. and then biaxiallystretched at 160° C. at a rate of 500% per minute.

    ______________________________________                                                                              Elong                                           %       Tensile     Tensile   Break                                   Direction                                                                             Stretch Mod. (Kpsi) Strength (Kpsi)                                                                         %                                       ______________________________________                                        X       200     1800        34        2.9                                     Y       100      400         2        2.3                                     ______________________________________                                    

EXAMPLE 17

59.6 grams (0.2 moles) of 3,4'-dihydroxybenzophenone diacetate, 16.6grams (0.1 mole) of terephthalic acid, 16.6 grams (0.1 mole) ofisophthalic acid and 54 grams (0.3 mole) of p-hydroxybenzoic acidacetate were introduced into a glass polycondensation reactor. Afterpurging, the reactor was heated using a Wood's metal bath from 185° C.to 205° C. for 2 hrs. 30 min.; 33 ml. acetic acid was collected. Thetemperature was increased to 330° C. for 30 min. Then nitrogen was blownin for 25 min. Partial vacuum (5 KPa) was applied for 15 min., then fullvacuum (0.03 KPa) for 45 min. at 330° C. and 3 hours at 340° C. Theyield of polymer was 92% (96 g)--the inherent viscosity was 1.6 dlg⁻¹.The Tg was 106° C. as determined by DSC, and a ΔH_(f) of 0 J./g.

The polymer was compression molded at 320° C. and then uniaxiallystretched at 200° C. at a rate of 500% per minute.

    ______________________________________                                                                              Elong                                           %       Tensile     Tensile   Break                                   Direction                                                                             Stretch Mod. (Kpsi) Strength (Kpsi)                                                                         %                                       ______________________________________                                        X       200     2000        54         3                                      X        0       500        12        38                                      ______________________________________                                    

EXAMPLE 18

One hundred twelve grams (0.3 mole) of3-hydroxy-4'(4-hydroxyphenyl)benzophenone diacetate and 51 grams (0.3mole) of 1,4 transcyclohexane dicarboxylic acid were simultaneouslyintroduced into a glass polycondensation reactor fitted with amechanical stirrer, nitrogen inlet, vacuum outlet and a refluxcondenser. After purging, the reactor was heated using a Wood's metalbath at from 185° C. to 300° C. for 1 hr 35 mins. Thirty-three ml ofacetic acid, which was 96% of expected amount, was collected. Thennitrogen was blown in for 1 hr. Partial vacuum (5 KPa) was applied for15 mins., then full vacuum (0.03 KPa) for 20 mins. at 320° C., 45 mins.at 330° C., and 3 hrs 40 mins. at 350° C. The yield of polymer was 96%(122 grams). The inherent viscosity was 1.4 dlg⁻¹. The Tg was 110° C. asdetermined by DSC. It had no crystalline phase melting point transition,at ΔH_(f) =0 J/g.

EXAMPLE 19

One hundred fifty grams (0.4 mole) of3-hydroxy-4'-(4-hydroxyphenyl)benzophenone diacetate, 33 grams (0.2mole) of terephthalic acid and 33 grams (0.2 mole) of isophthalic acidwere simultaneously introduced into a glass polycondensation as inExample 1. After purging with nitrogen, the reactor was heated from 100°C. to 250° C. for 1 hr 20 mins., then 2 hrs at 270° C. Thirty-three cc(70%) of the expected acetic acid was collected. Nitrogen was blown infor 45 mins. Partial vacuum (5 KPa) was applied for 15 mins. at 290° C.then full vacuum (0.03 KPa) for 2 hrs 40 mins. Another vacuum (0.04 KPa)at 300° C. was needed for 6 hrs 30 mins. The inherent viscosity was 1dlg⁻¹. The Tg was 138° C. as determined by DSC, ΔH_(f) was 0 J./g. Thepolymer formed a liquid crystalline phase up to above 350° C. asdetermined by optical microscope. Tough film was compression molded at220° C. under 4500 kg for 1 min. It was biaxially stretched at 190° C.to 200% to give a smooth, shiny, and balanced film. Physical propertiesof a film (40 μm or 1.5 mil thick) were:

    ______________________________________                                        Tensile Modulus Kpsi (MPa)                                                                           800    (5,500)                                         Tensile Strength Kpsi (MPa)                                                                          51     (350)                                           Elongation at Break, % 10                                                     ______________________________________                                    

EXAMPLE 20

One hundred fifty grams (0.4 mole) of3-hydroxy-4'-(4-hydroxyphenyl)benzophenone diacetate, 46.5 grams (0.28)of terephthalic acid and 20 grams (0.12 mole) of isophthalic acid weresimultaneously introduced into a glass polycondensation reactor as inExample 1. After purging with nitrogen, the reactor was heated using aWood's metal bath from 185° C. to 300° C. for 2 hrs. Forthy-one cc (85%)of acetic acid was collected. Nitrogen was blown in for 10 mins. Partialvacuum (5 KPa) was applied for 30 mins. then full vacuum (0.03 KPa) for3 hrs 30 mins. The yield was 96% (162 grams). The inherent viscosity was1 dlg⁻¹. The Tg was 127° C. as determined by DSC, ΔH_(f) was 0 J./g. Thepolymer had a liquid crystalline phase up to above 350° C. as determinedby optical microscope.

The above polyester was compression molded at 220° C. for 1 min. It wasbiaxially stretched at 185° C. to 200% to give a smooth, shiny film.Physical properties of a nonheat-treated film (25 μm or 1 mil thick)were:

    ______________________________________                                        Tensile Modulus Kpsi (MPa)                                                                          1800   (12,400)                                         Tensile Strength Kpsi (MPa)                                                                         34     (230)                                            Elongation at Break, %                                                                              3                                                       ______________________________________                                    

EXAMPLE 21

One hundred twelve and two-tenths grams (0.3 mole) of3-hydroxy-4'-(4-hydroxyphenyl)benzophenone diacetate, 39.8 grams (0.24mole) of terephthalic acid and 10 grams (0.06 mole) of isophthalic acidwere simultaneously introduced into a glass polycondensation reactor asin Example 1. After purging with nitrogen, the reactor was heated usinga Wood's metal bath from 185° C. to 300° C. for 2 hrs 15 mins.Thirty-one cc (91%) of acetic acid was collected. Nitrogen was blown infor 15 mins. Partial vacuum (5 KPa) was applied for 15 mins. and fullvacuum (0.03 KPa) for 1 hr 5 mins. at 300° C. and 3 hrs 40 mins. at 310°C. The yield was 94% (120 grams). The inherent viscosity was 1.1 dlg⁻¹.The Tg was 118° C. as determined by DSC, ΔH_(f) was 0 J./g. The polymerhad a liquid crystalline phase up to above 350° C. as determined byoptical microscope.

The above polymer was compression molded at 220° C. for 1 min. It wasbiaxially stretched at 185° C. up to 300% to give a smooth, shiny andbalanced film. Physical properties of a nonheat-treated film 50 μm or 2mil were:

    ______________________________________                                        Tensile Modulus Kpsi (MPa)                                                                          2200   (15,200)                                         Tensile Strength Kpsi (MPa)                                                                         33     (230)                                            Elongation at Break, %                                                                              2                                                       ______________________________________                                    

EXAMPLE 22

One hundred thirty-one grams (0.35 mole) of3-hydroxy-4'-(4-hydroxyphenyl)benzophenone diacetate, 49.4 grams (0.3mole) of terephthalic acid and 8.7 grams (0.05 mole) of isophthalic acidwere simultaneously introduced into a glass polycondensation reactor asin Example 1. After purging with nitrogen, the reactor was heated usinga Wood's metal bath from 185° C. to 300° C. for 2 hrs 5 mins.Thirty-five cc (83%) of acetic acid was collected. Nitrogen was blown infor 10 mins. Partial vacuum (5 KPa) was applied for 15 mins. and fullvacuum (0.03 KPa) for 1 hr 30 mins. at 300° C. and 3 hrs 30 mins. at310° C. The yield was 93% (136 grams). The inherent viscosity was 1.2dlg⁻¹. This polymer had a ΔH_(f) of 1.92 J/g and for this reason isoutside the scope of the present invention. The Tg was 112° C. asdetermined by DSC. The polymer had a liquid crystalline phase up toabove 350° C. as determined by optical microscope.

The above polymer was compression molded at 220° C. for 1 min. It couldnot be biaxially stretched at 185° C. to give an oriented film. This wasa strong distinction from polymers of the present invention wherecompression molded film could be biaxially stretched.

EXAMPLE 23

One hundred thirty-one grams (0.35 mole) of3-hydroxy-4'-(4-hydroxyphenyl)benzophenone diacetate, 52.3 grams (0.315mole) of terephthalic acid, 5.8 grams (0.035 mole) of isophthalic acidwere simultaneously introduced into a glass polycondensation reactor asin Example 1. After purging with nitrogen, the reactor was heated usinga Wood's metal bath from 185° C. to 300° C. for 2 hrs 15 mins.Thirty-four cc (85%) of acetic acid was collected. Nitrogen was blown infor 15 mins. Partial vacuum (5 KPa) was applied for 15 mins. and fullvacuum (0.03 KPa) for 1 hr 30 mins. at 300° C. and 2 hrs 30 mins. at310° C. The yield was 89% (132 grams). The inherent viscosity was 1dlg⁻¹. The Tg was 116° C. as determined by DSC. This polymer had a solidcrystalline-liquid crystalline transition at 230° C. with a ΔH_(f) of5.3 J./g and for this reason is outside the scope of the presentinvention. The polymer had a liquid crystalline phase up to above 350°C. as determined by optical microscope.

The above polymer was compression molded at 220° C. for 1 min to give avery brittle film. It could not be biaxially stretched at <185° C. togive an oriented film. This was a strong distinction from Example 21where compression molded film could be biaxially stretched.

EXAMPLE 24

Fourteen and nine-tenths grams (0.04 mole) of3-hydroxy-4'-(4-hydroxyphenyl)benzophenone diacetate and 6.6 grams (0.04mole) of terephthalic acid were simultaneously introduced into a glasspolycondensation reactor as in Example 2. After purging with nitrogen,the reactor was heated using a Wood's metal bath from 185° C. to 300° C.for 1 hr 30 mins. Four cc (83%) of acetic acid was collected. Nitrogenwas blown in for 45 mins. Partial vacuum (5 KPa) was applied for 5 mins.and full vacuum (0.03 KPa) for 3 hrs at 300° C. and 1 hr 25 mins. at320° C. The yield of polymer was 72% of theoretical (12 grams). The Tgat 107° C. and a transition solid crystalline-liquid crystalline at 291°C. were determined by DSC. The ΔH_(f) was 7.7 J./g. The liquidcrystalline liquid phase persisted up to above 350° C. as determined byoptical microscope. Compression-molded film at 340° C. was very brittleand could not be stretched as in Example 21.

Examples 25 and 27 illustrate that some of the ester links of thepolymers of the present invention can be replaced with amide linkswithout materially affecting the essential properties of the resultingpolymers.

EXAMPLES 25-26

X grams of 3-hydroxy-4'-(4-hydroxyphenyl)-benzophenone diacetate, ygrams of p-aminophenol diacetate, z grams of terephthalic acid and kgrams of isophthalic acid were simultaneously added into a glasspolycondensation reactor as in Example 2. After purging, the reactor washeated to 260° C. for 2 hrs 30 mins. then for 1 hr at 300° C. Usually 3to 4 cc of acetic acid were collected. Nitrogen was blown in for 30mins. Partial vacuum (5 KPa) was applied for 10 mins. and full vacuum(0.03 KPa) for 3 hrs. The yield was almost quantitative (90-95%). Thecomposition, the inherent viscosity (I.V. dlg⁻¹) the Tg °C. (asdetermined by DSC), the injection-molding temperature (°C.) and thetensile strength of nonheat-treated samples and the ΔH_(f) are reportedin Table I.

                                      TABLE I                                     __________________________________________________________________________    mPCOPPG*  Aminophenol                                                                          Terephth.                                                                            Isophth.                                              Diacetate Diacetate                                                                            Acid   Acid          Inj.                                                                              Ten.                                x Mole    y Mole z Mole k Mole Tg.                                                                              I.V.                                                                              Temp.                                                                             Strength                                                                             ΔH.sub.f               Ex.                                                                              g Ratio %                                                                            g Ratio %                                                                            g Ratio %                                                                            g Ratio %                                                                            °C.                                                                       dlg.sup.-1                                                                        °C.                                                                        Kpsi                                                                             (MPa)                                                                             J./g                         __________________________________________________________________________    25 9 60   3.1                                                                             40   3.3                                                                             50   3.3                                                                             50   154                                                                              1.2 280 16.4                                                                             (110)                                                                             0                            26 7.5                                                                             50   3.8                                                                             50   3.3                                                                             50   3.3                                                                             50   163                                                                              1   280 17 (117)                                                                             0                            __________________________________________________________________________     *mPCOPPG diacetate = 3 hydroxy,4'(hydroxy phenyl)benzophenone diacetate  

EXAMPLE 27

Thirteen and four-tenths grams (0.036 mole) of3-hydroxy-4'-(4-hydroxyphenyl)benzophenone diacetate, 0.77 gram (0.004mole) of p-phenylene diamine diacetate, 3.3. grams (0.02 mole) ofterephthalic acid and 3.3 grams (0.02 mole) of isophthalic acid weresimultaneously introduced into a glass polycondensation reactor as inExample 2. After purging with nitrogen, the reactor was heated using aWood's metal bath from 100° C. to 260° C. for 1 hr 45 mins., then to280° C. for 2 hrs. Three cc (63%) of acetic acid was collected. Nitrogenwas blown in for 45 mins. Partial vacuum (5 KPa) was applied for 10mins. and full vacuum (0.03 KPa) for 45 mins. at 280° C. and 2 hrs at300° C. The yield was 94% (15 grams). The inherent viscosity was 0.8dlg⁻¹. The Tg was 148° C. as determined by DSC, and a ΔH_(f) of 0 J./g.It had a liquid crystalline phase up to above 350° C. as determined byoptical microscope.

I claim:
 1. A melt anisotropic polyester having an inherent viscosity ofat least 0.5 as measured from a 0.5 g solution of polymer in 100 ml ofan equal volume mixture of p-chlorophenol and 1,2-dichloroethane, and aheat of fusion of less than 1.5 joule per gram consisting essentially ofat least 10 mole percent glycol derived repeating units of the structure##STR4## and the remainder, repeating glycol derived units of thestructure --O--R--O-- where --R-- is an arylene group containing 6-14carbon atoms, and diacid derived repeating units of the structure##STR5## where --R'-- is an alkylene group containing 4 to 14 carbonatoms or an arylene group consisting 6 to 14 carbon atoms andmonoacid-monohydroxy derived repeating units of the structure ##STR6##where --R"-- is an arylene containing 6 to 14 carbon atoms.
 2. Thepolyester of claim 1 wherein --R'-- is alkylene and from 45 to 50 per100 glycol derived repeating units are ##STR7##
 3. The polyester ofclaim 2 wherein from 45 to 50 per 100 glycol derived repeating units are##STR8##
 4. The polyester of claim 1 consisting essentially of repeatingunits ##STR9## and units of the structure ##STR10## wherein from 20 to90 per per 100 diacid derived repeating units are --R'-- units of thestructure ##STR11## and from 80 to 10 per 100 glycol derived repeatingunits are --R'-- units of the structure ##STR12##
 5. The polyester ofclaim 4 wherein from 20 to 90 per 100 diacid derived repeating units are--R'-- units of the structure ##STR13##
 6. The polyester of claim 5wherein the --R'-- units are ##STR14##
 7. The polyester of claim 5wherein the glycol derived repeating units are ##STR15##
 8. Thepolyester of claim 7 wherein from 20 to 70 per 100 glycol derivedrepeating units are --R'-- units of the structure ##STR16##
 9. Thepolyester of claim 8 wherein from 30 to 60 per 100 glycol derivedrepeating units are --R'-- units of the structure ##STR17##
 10. Thepolyester of claim 9 wherein the remaining --R'-- units are ##STR18##11. The polyester of claim 4 wherein the glycol derived repeating unitsare ##STR19## and from 20 to 60 per 100 glycol derived repeating unitsare --R'-- units of the structure ##STR20##
 12. The polyester of claim11 wherein from 20 to 50 per 100 glycol derived repeating units are--R'-- units of the structure ##STR21##
 13. The polyester of claim 12wherein from 20 to 40 per 100 glycol derived repeating units are --R'--units of the structure ##STR22##
 14. The polyester of claim 13 whereinthe remaining --R'-- units are ##STR23##
 15. The polyester of claim 1wherein from 10 to 80 per 100 diacid derived repeating units are --R'--units of the structure ##STR24## the remaining --R'-- units are##STR25## and from 70 to 100 per 100 glycol derived units are units ofthe structure ##STR26## and the remaining glycol derived repeating unitsare ##STR27##
 16. The polyester of claim 15 wherein from 20 to 90 per100 diacid derived units are --R'-- units of the structure ##STR28## 17.The polyester of claim 16 wherein from 30 to 70 per 100 diacid derivedrepeating units are --R'-- units of the structure ##STR29## and theremaining --R'-- units are ##STR30## and 80 to 100 per 100 glycolderived repeating units are ##STR31##
 18. The polyester of claim 1wherein from 10 to 80 per 100 diacid derived repeating units are --R'--units of the structure ##STR32## and the remaining --R'-- units are##STR33## from 30 to 100 per 100 glycol derived repeating units are##STR34## and the remaining glycol repeating units are ##STR35## where--X is --F, --Cl, or --Br.
 19. The polyester of claim 18 wherein from 20to 90 per 100 diacid repeating units are --R'-- of the structure##STR36##
 20. The polyester of claim 19 wherein from 30 to 70 per 100diacid derived repeating units are --R'-- units of the structure##STR37## the remaining --R'-- units are units of the structure##STR38## and from 40 to 100 per 100 glycol derived repeating units areunits of the structure ##STR39##
 21. The polyester of claim 1 whereinfrom 30 to 80 per 100 diacid derived repeating units are --R'-- units ofthe structure ##STR40## the remaining --R'-- units are ##STR41## andfrom 20 to 100 per 100 glycol derived repeating units are units of thestructure ##STR42## and the remaining glycol derived repeating units are##STR43## where --R'" is --H, --CH₃, --C₂ H₅ or --Cl.
 22. The polyesterof claim 21 wherein --R'" is H.
 23. The polyester of claim 22 whereinfrom 20 to 70 per 100 diacid repeating units are --R'-- units of thestructure ##STR44##
 24. The polyester of claim 23 wherein --R'" is --H.25. The polyester of claim 24 wherein from 30 to 70 per 100 diacidderived repeating units are --R'-- units of the structure ##STR45## 26.The polyester of claim 25 wherein from 0 to 50 per 100 glycol derivedrepeating units are units of the structure ##STR46##
 27. The polyesterof claim 1 wherein from 10 to 80 per 100 diacid derived repeating unitsare --R'-- units of the structure ##STR47## the remaining --R'-- unitsare ##STR48## from 80 to 100 per 100 glycol derived repeating units areunits of the structure ##STR49## and the remaining glycol derivedrepeating units are ##STR50##
 28. The polyester of claim 27 wherein from20 to 90 per 100 diacid derived repeating units are --R'-- units of thestructure ##STR51##
 29. The polyester of claim 28 wherein from 30 to 70per 100 diacid repeating units are --R'-- units of the structure##STR52## and from 85 to 100 per 100 glycol derived repeating units areunits of the structure ##STR53##
 30. The polyester of claim 1 whereinfrom 10 to 80 per 100 diacid derived repeating units are --R'-- units ofthe structure ##STR54## the remaining --R'-- units are ##STR55## from 30to 100 per 100 glycol derived repeating units are units of the structure##STR56## and the remaining glycol derived repeating units are ##STR57##where --R"" is --CH₃, --C₂ H₅, --O--CH₃, or --OC₂ H₅.
 31. The polyesterof claim 30 wherein from 20 to 90 per 100 diacid derived repeating unitsare --R'-- units of the structure ##STR58##
 32. The polyester of claim31 wherein from 30 to 70 per 100 diacid derived repeating units are--R'-- units of the structure ##STR59## and from 50 to 100 per 100glycol derived repeating units are units of the structure ##STR60## 33.The polyester of claim 1 wherein from 25 to 80 per 100 diacid derivedrepeating units are --R'-- units of the structure ##STR61## theremaining --R'-- units are ##STR62## from 70 to 100 per 100 glycolderived repeating units are units of the structure ##STR63## and theremaining glycol derived repeating units are of the structure ##STR64##34. The polyester of claim 33 wherein from 20 to 75 per 100 diacidderived repeating units are --R'-- units of the structure ##STR65## 35.The polyester of claim 34 wherein from 35 to 70 per 100 diacid derivedrepeating units are --R'-- units of the structure ##STR66## and from 80to 100 per 100 glycol derived repeating units are units of the structure##STR67##
 36. The polyester of claim 1 wherein from 40 to 80 per 100diacid derived repeating units are --R'-- units of the structure##STR68## and the remaining --R'-- units are ##STR69## from 80 to 100per 100 glycol derived repeating units are units of the structure##STR70## and the remaining glycol derived repeating units are ##STR71##37. The polyester of claim 36 wherein from 20 to 60 per 100 diacidderived repeating units are --R'-- units of the structure ##STR72## 38.The polyester of claim 37 wherein 55 to 70 per 100 diacid derivedrepeating units are --R'-- units of the structure ##STR73## and from 87to 100 per 100 glycol derived repeating units are units of the structure##STR74##
 39. The polyester of claim 1 wherein from 40 to 80 per 100diacid repeating units are --R'-- units of the structure ##STR75## theremaining --R'-- units are ##STR76## from 55 to 100 per 100 glycolderived repeating units are units of the structure ##STR77## and theremaining glycol derived repeating units are ##STR78## where --X is --F,--Cl or --Br.
 40. The polyester of claim 39 wherein from 20 to 60 per100 diacid derived repeating units are --R'-- units of the structure##STR79##
 41. The polyester of claim 40 wherein from 40 to 80 per 100diacid derived repeating units are of the structure --R'-- units##STR80## and from 60 to 100 per 100 glycol derived repeating units areunits of the structure ##STR81##
 42. The polyester of claim 1 whereinfrom 65 to 80 per 100 diacid derived repeating units are --R'-- units ofthe structure ##STR82## the remaining --R'-- units are ##STR83## from 45to 100 per 100 glycol derived repeating units are units of the structure##STR84## and the remaining glycol derived repeating units are ##STR85##wherein --R"' is --H, --CH₃, --C₂ H₅ or --Cl.
 43. The polyester of claim42 wherein --R'" is --H.
 44. The polyester of claim 43 wherein from 20to 35 per 100 diacid derived repeating units are --R'-- units of thestructure ##STR86##
 45. The polyester of claim 44 wherein from 65 to 80per 100 diacid derived repeating units are --R'-- units of the structure##STR87## and from 55 to 100 per 100 glycol derived repeating units areunits of the structure ##STR88##
 46. The polyester of claim 1 whereinfrom 40 to 80 per 100 diacid derived repeating units are --R'-- unitsare ##STR89## and the remaining --R'-- units are ##STR90## from 85 to100 per 100 glycol derived repeating units are units of the structure##STR91## and the remaining glycol derived repeating units are ##STR92##47. The polyester of claim 46 wherein from 20 to 60 per 100 diacidderived repeating units are --R'-- units of the structure ##STR93## 48.The polyester of claim 47 wherein from 55 to 70 per 100 diacid derivedrepeating units are --R'-- units of the structure ##STR94## and from 90to 100 per 100 glycol derived repeating units are units of the structure##STR95##
 49. The polyester of claim 1 wherein from 50 to 80 per 100diacid derived repeating units are --R'-- units of the structure##STR96## the remaining --R'-- units are ##STR97## or from 30 to 100glycol derived repeating units are of the structure ##STR98## and theremaining glycol derived repeating units are ##STR99## where --R"" is--CH₃, --C₂ H₅ or --OCH₃ or --OC₂ H₅.
 50. The polyester of claim 49wherein from 20 to 50 per 100 diacid derived repeating units are --R'--units of the structure ##STR100##
 51. The polyester of claim 50 whereinfrom 50 to 80 per 100 diacid repeating units are --R'-- units of thestructure ##STR101## and from 50 to 100 glycol derived repeating unitsare of the structure ##STR102##
 52. The polyester of claim 1 whereinfrom 40 to 70 per 100 diacid derived repeating units are --R'-- units ofthe structure ##STR103## the remaining --R'-- units are ##STR104## from80 to 100 per 100 glycol derived repeating units are units of thestructure ##STR105## and the remaining glycol derived repeating unitsare ##STR106##
 53. The polyester of claim 52 wherein from 30 to 60 per100 diacid derived repeating units are units of the structure ##STR107##54. The polyester of claim 53 wherein from 55 to 70 per 100 diacidderived repeating units are --R'-- units of the structure ##STR108## andfrom 85 to 100 per 100 glycol derived repeating units are units of thestructure ##STR109##
 55. The polyester of claim 1 wherein the glycolderived units are ##STR110## there are from 20 to 100 per 100 diacidderived repeating units of --R'-- units of the structure ##STR111## from0 to 80 per 100 diacid derived repeating units are --R'-- units of thestructure ##STR112## and 100 to 300 per 100 glycol derived repeatingunits, are hydroxy-acid derived --R"-- units of the structure ##STR113##56. The polyester of claim 55 wherein from 20 to 100 per 100 diacidderived repeating units are --R'-- units of the structure ##STR114## 57.The polyester of claim 56 wherein there are from 30 to 100 per 100diacid derived repeating units --R'-- units of the structure ##STR115##and from 150 to 250 per 100 glycol derived repeating units arehydroxy-acid derived --R"-- units.
 58. The polyester of claim 57 whereinthere are from 50 to 100 per 100 diacid derived repeating units --R'--units of the structure ##STR116## from 0 to 50 per 100 diacid derivedrepeating units --R'-- units of the structure ##STR117## and from 150 to200 per 100 glycol derived repeating units --R"-- units of the structure##STR118##
 59. The polyester of claim 1 wherein the glycol derived unitsare ##STR119## there are from 10 to 80 per 100 diacid derived repeatingunits --R'-- units of the structure ##STR120## from 20 to 90 per 100diacid derived units --R'-- units of the structure ##STR121## and from30 to 99 per 100 glycol derived repeating units --R"-- units of thestructure ##STR122##
 60. The polyester of claim 59 wherein there arefrom 10 to 80 per 100 diacid derived repeating units are --R'-- units ofthe structure ##STR123##
 61. The polyester of claim 60 wherein there arefrom 15 to 35 per 100 diacid derived repeating units --R'-- units of thestructure ##STR124##
 62. The polyester of claim 61 wherein there arefrom 25 to 35 per 100 diacid derived repeating units --R'-- units of thestructure ##STR125## from 65 to 75 per 100 diacid derived repeatingunits --R'-- units of the structure ##STR126## and the --R"-- units are##STR127##
 63. The polyester of claim 1 wherein the glycol derivedrepeating units are ##STR128## there are from 20 to 70 per 100 diacidderived repeating units are --R'-- units of the structure ##STR129##from 30 to 80 per 100 glycol derived repeating units --R'-- of thestructure ##STR130## and from 100 to 300 per 100 glycol derivedrepeating units are hydroxy-acid derived --R"-- units of the structure##STR131##
 64. The polyester of claim 63 wherein there are from 20 to 70per 100 diacid derived repeating units are --R'-- units of the structure##STR132##
 65. The polyester of claim 64 wherein there are from 30 to 70per 100 diacid derived repeating units --R'-- units of the structure##STR133## from 30 to 70 per 100 diacid derived repeating units --R'--units of the structure ##STR134## and from 150 to 250 per 100 glycolderived repeating units --R"-- units.
 66. The polyester of claim 65wherein there are from 50 to 70 per 100 diacid derived repeating units--R'-- units of the structure ##STR135## from 30 to 50 per 100 diacidderived repeating units --R'-- units of the structure ##STR136## andfrom 150 to 200 per 100 glycol derived repeating units --R"-- units ofthe structure ##STR137##
 67. The polyester of claim 1 wherein the glycolderived units are ##STR138## there are from 10 to 55 per 100 diacidderived repeating units --R'-- units of the structure ##STR139## from 45to 90 per 100 diacid derived repeating units --R'-- units of thestructure ##STR140## and from 30 to 99 per 100 glycol derived repeatingunits are hydroxy-acid derived --R"-- units of the structure ##STR141##68. The polyester of claim 67 wherein from 45 to 90 per 100 diacidderived repeating units are --R'-- units of the structure ##STR142## 69.The polyester of claim 68 wherein there are from 15 to 35 per 100 diacidderived repeating units --R'-- units of the structure ##STR143##
 70. Thepolyester of claim 69 wherein from 25 to 35 per 100 diacid derivedrepeating units are --R'-- units of the structure ##STR144## and from 65to 75 per 100 diacid derived repeating units are --R'-- units of thestructure ##STR145## and the --R"-- units are ##STR146##
 71. Thepolyester of claim 1 wherein from 70 to 100 per 100 glycol derivedrepeating units are ##STR147## from 0 to 30 per 100 glycol derivedrepeating units are ##STR148## from 0 to 100 per 100 diacid derivedrepeating units are --R'-- units of the structure ##STR149## and 100 to0 per 100 diacid derived repeating units are diacid derived repeatingunits of the structure ##STR150## and from 100 to 300 per 100 diacidderived repeating units are hydroxy-acid derived --R"-- units of thestructure ##STR151##
 72. The polyester of claim 71 wherein from 30 to100 per 100 diacid derived repeating units are --R'-- units of thestructure ##STR152## and from 100 to 250 per 100 glycol derived unitsare --R"-- units.
 73. The polyester of claim 72 wherein from 50 to 100per 100 diacid derived repeating units are --R'-- units of the structure##STR153## from 50 to 0 per 100 diacid derived repeating units are--R'-- units of the structure ##STR154## and 100 to 200 per 100 glycolderived units are hydroxy-acid derived --R"-- units of the structure##STR155##
 74. The polyester of claim 1 wherein from 30 to 100 per 100glycol derived repeating units are ##STR156## and from 0 to 70 per 100glycol derived repeating units are units of the structure ##STR157##where --X is --F, --Cl or --Br, from 0 to 100 per 100 diacid derivedrepeating units are --R'-- units of the structure ##STR158## from 0 to100 per 100 diacid derived repeating units are --R'-- units of thestructure ##STR159## and from 100 to 300 per 100 glycol derivedrepeating units are hydroxy-acid derived --R"-- units of the structure##STR160##
 75. The polyester of claim 74 wherein from 30 to 100 per 100diacid derived repeating units are --R'-- units of the structure##STR161## and from 100 to 250 per 100 glycol derived repeating unitsare hydroxy-acid derived --R"-- units.
 76. The polyester of claim 75wherein from 50 to 100 per 100 diacid derived repeating units are --R'--units of the structure ##STR162## from 0 to 50 per 100 diacid derivedrepeating units are --R'-- units of the structure ##STR163## and from100 to 200 per 100 glycol derived repeating units are hydroxy-acidderived --R"-- units of the structure ##STR164##
 77. The polyester ofclaim 1 wherein from 30 to 100 per 100 glycol derived repeating unitsare ##STR165## and 0 to 70 per 100 glycol derived repeating units areunits of the structure ##STR166## where --R'" is --H or --CH₃, --C₂ H₅or --Cl, from 0 to 100 per 100 diacid derived repeating units are --R'--units of the structure ##STR167## from 0 to 100 per 100 diacid derivedrepeating units are --R'-- units of the structure ##STR168## and from100 to 300 per 100 glycol derived repeating units are --R'-- units ofthe structure ##STR169##
 78. The polyester of claim 77 wherein from 30to 100 per 100 diacid derived repeating units are --R'-- units of thestructure ##STR170## and from 100 to 250 per glycol derived repeatingunits are hydroxy-acid derived --R"-- units.
 79. The polyester of claim78 wherein from 50 to 100 per 100 diacid derived repeating units are--R'-- units of the structure ##STR171## from 0 to 50 per 100 diacidderived repeating units are units of the structure ##STR172## and from100 to 200 per 100 glycol derived repeating units are hydroxy-acidderived --R"-- units of the structure ##STR173##
 80. The polyester ofclaim 79 wherein --R'" is --H.
 81. The polyester of claim 1 wherein from80 to 100 per 100 glycol derived repeating units are units of thestructure ##STR174## from 0 to 20 per 100 glycol derived repeating unitsare units of the structure ##STR175## from 0 to 100 per 100 diacidderived repeating units are --R'-- units of the structure ##STR176##from 0 to 100 per 100 diacid derived repeating units are --R'-- units ofthe structure ##STR177## and from 100 to 300 per 100 glycol derivedrepeating units are hydroxy-acid derived --R"-- units of the structure##STR178##
 82. The polyester of claim 81 wherein from 30 to 100 per 100diacid derived repeating units are --R'-- units of the structure##STR179## and from 100 to 250 per glycol derived repeating units arehydroxy-acid derived --R"-- units.
 83. The polyester of claim 82 whereinfrom 50 to 100 per 100 diacid derived repeating units are --R'-- unitsof the structure ##STR180## from 0 to 50 per 100 glycol derivedrepeating units are --R"-- units of the structure ##STR181## and from100 to 200 per 100 glycol derived repeating units are hydroxy-acidderived --R"-- units of the structure ##STR182##
 84. The polyester ofclaim 1 wherein from 30 to 100 per 100 glycol derived repeating unitsare units of the structure ##STR183## from 0 to 70 per 100 glycolderived repeating units are units of the structure ##STR184## where--R"" is --CH₃, --C₂ H₅, --OCH₃ or --OC₂ H₅, from 0 to 100 per 100diacid derived repeating units are --R'-- units of the structure##STR185## from 0 to 100 per 100 diacid derived repeating units areunits of the structure ##STR186## and from 100 to 300 per 100 glycolderived repeating units are hydroxy-acid derived --R"-- units of thestructure ##STR187##
 85. The polyester of claim 84 wherein from 30 to100 per 100 diacid derived repeating units are --R'-- units of thestructure ##STR188## and from 100 to 250 per 100 glycol derivedrepeating units are hydroxy-acid derived --R"-- units.
 86. The polyesterof claim 85 wherein from 50 to 100 per 100 diacid derived repeatingunits are --R'-- units of the structure ##STR189## from 0 to 50 per 100diacid derived repeating units are --R'-- units of the structure##STR190## and from 100 to 200 per 100 glycol derived repeating unitsare hydroxy-acid derived --R"-- units of the structure ##STR191## 87.The polyester of claim 1 wherein from 70 to 100 per 100 glycol derivedrepeating units are units of the structure ##STR192## and 0 to 30 per100 glycol derived repeating units of the structure ##STR193## from 0 to100 per 100 diacid derived repeating units are --R'-- units of thestructure ##STR194## from 0 to 100 per 100 diacid derived repeatingunits are --R'-- units of the structure ##STR195## and from 100 to 300per 100 glycol derived repeating units are hydroxy-acid derived --R"--units of the structure ##STR196##
 88. The polyester of claim 87 whereinfrom 30 to 100 per 100 diacid derived repeating units are units of thestructure ##STR197## and from 100 to 250 per 100 glycol derivedrepeating units are hydroxy-acid derived --R"-- units.
 89. The polyesterof claim 88 wherein from 50 to 100 per 100 diacid derived repeatingunits are units of the structure ##STR198## from 0 to 50 per 100 diacidderived repeating units are --R'-- units of the structure ##STR199## andfrom 100 to 200 per 100 glycol derived repeating units are hydroxy-acid--R"-- units of the structure ##STR200##
 90. The polyester of claim 1wherein from 80 to 100 per 100 glycol derived repeating units are unitsof the structure ##STR201## and from 0 to 20 per 100 glycol derivedrepeating units are units of the structure ##STR202## from 0 to 65 per100 diacid derived repeating units are --R'-- units are of the structure##STR203## from 35 to 100 per 100 diacid derived repeating units are--R'-- units of the structure ##STR204## and from 100 to 300 per 100glycol derived repeating units are hydroxy-acid derived --R"-- units ofthe structure ##STR205##
 91. The polyester of claim 90 wherein from 30to 65 per 100 diacid derived repeating units are --R'-- units of thestructure ##STR206## and from 100 to 250 per 100 glycol derivedrepeating units are hydroxy-acid derived --R"-- units.
 92. The polyesterof claim 91 wherein from 50 to 65 per 100 diacid derived repeating unitsare --R'-- units of the structure ##STR207## from 35 to 50 per 100diacid derived repeating units are --R'-- units of the structure##STR208## and from 100 to 200 per 100 glycol derived repeating unitsare hydroxy-acid derived --R"-- units of the structure ##STR209## 93.The polyester of claim 1 wherein from 55 to 100 per 100 glycol derivedrepeating units are units of the structure ##STR210## and from 0 to 45per 100 glycol derived repeating units are units of the structure##STR211## where --X is --H --F, --Cl, or --Br, from 0 to 65 per 100diacid derived repeating units are --R'-- units of the structure##STR212## from 35 to 100 per 100 diacid derived repeating unit are--R'-- units of the structure ##STR213## and from 100 to 300 per 100glycol derived repeating units are hydroxy-acid derived --R"-- units ofthe structure ##STR214##
 94. The polyester of claim 93 wherein from 30to 65 per 100 diacid derived repeating units are --R'-- units of thestructure ##STR215## and from 100 to 250 per 100 glycol derivedrepeating units are hydroxy-acid derived --R' units.
 95. The polyesterof claim 94 wherein from 50 to 65 per 100 diacid derived repeating unitsare --R'-- units of the structure ##STR216## from 35 to 50 per 100diacid derived repeating units are --R'-- units of the structure##STR217## and from 100 to 200 per 100 glycol derived repeating unitsare hydroxy-acid derived --R"-- units of the structure ##STR218## 96.The polyester of claim 1 wherein from 55 to 100 per 100 glycol derivedrepeating units are units of the structure ##STR219## and from 0 to 45per 100 glycol derived repeating units are units of the structure##STR220## where --R'" is --H --CH₃, --C₂ H₅ or --Cl from 0 to 65 per100 diacid derived repeating units are --R'-- units of the structure##STR221## from 35 to 100 per 100 diacid derived repeating units are--R'-- units of the structure ##STR222## and from 100 to 300 per 100glycol derived repeating units are hydroxy-acid derived --R"-- units ofthe structure ##STR223##
 97. The polyester of claim 96 wherein from 30to 65 per 100 diacid derived repeating units are --R'-- units of thestructure ##STR224## and from 100 to 250 per 100 glycol derivedrepeating units are hydroxy-acid derived --R"-- units.
 98. The polyesterof claim 97 wherein from 50 to 65 per 100 diacid derived repeating unitsare --R'-- units of the structure ##STR225## from 35 to 50 per 100diacid derived repeating units are --R'-- units of the structure##STR226## and from 100 to 200 per 100 glycol derived repeating unitsare hydroxy-acid derived --R"-- units of the structure ##STR227## 99.The polyester of claim 98 wherein --R'" is --H.
 100. The polyester ofclaim 1 wherein from 85 to 100 per 100 glycol derived repeating unitsare units of the structure ##STR228## and from 0 to 15 per 100 glycolderived repeating units are units of the structure ##STR229## from 0 to65 per 100 diacid derived repeating units are --R'-- units of thestructure ##STR230## from 35 to 100 per 100 diacid derived repeatingunits are --R'-- units of the structure ##STR231## and from 100 to 300per 100 glycol derived repeating units are hydroxy-acid derived --R"--units of the structure ##STR232##
 101. The polyester of claim 100wherein from 30 to 65 per 100 diacid derived repeating units are --R'--units of the structure ##STR233## and from 100 to 250 per 100 glycolderived repeating units are hydroxy-acid derived --R"-- units.
 102. Thepolyester of claim 101 wherein from 50 to 65 per 100 diacid derivedrepeating units are --R'-- units of the structure ##STR234## from 35 to50 per 100 diacid derived repeating units are --R'-- units of thestructure ##STR235## and from 100 to 200 per 100 glycol derivedrepeating units are hydroxy-acid derived --R"-- units of the structure##STR236##
 103. The polyester of claim 1 wherein from 55 to 100 per 100glycol derived repeating units are units of the structure ##STR237##from 0 to 45 per 100 glycol derived repeating units are units of thestructure ##STR238## where --R"" is --CH₃ or --C₂ H₅, --O--CH₃, or--O--C₂ H₅, from 0 to 65 per 100 diacid derived repeating units are--R'-- units of the structure ##STR239## from 35 to 100 per 100 diacidderived repeating units are --R'-- units of the structure ##STR240## andfrom 100 to 300 per 100 glycol derived repeating units are hydroxy-acidderived --R"-- units of the structure ##STR241##
 104. The polyester ofclaim 103 wherein from 30 to 65 per 100 diacid derived repeating unitsare --R'-- units of the structure ##STR242## and from 100 to 250 per 100glycol derived repeating units are hydroxy-acid derived --R"-- units.105. The polyester of claim 104 wherein from 50 to 65 per 100 diacidderived repeating units are --R' units of the structure ##STR243## from35 to 50 per 100 diacid derived repeating units are --R'-- units of thestructure ##STR244## and from 100 to 200 per 100 glycol derivedrepeating units are hydroxy-acid derived --R"-- units of the structure##STR245##
 106. The polyester of claim 1 wherein from 80 to 100 per 100glycol derived repeating units of the structure ##STR246## from 0 to 20per 100 glycol derived repeating units are units of the structure##STR247## from 0 to 65 per 100 diacid derived repeating units are--R'-- units of the structure ##STR248## from 35 to 100 diacid derivedrepeating units are --R'-- units of the structure ##STR249## and from100 to 300 per 100 glycol derived repeating units are hydroxy-acidderived --R"-- units of the structure ##STR250##
 107. The polyester ofclaim 106 wherein from 30 to 65 per 100 diacid derived repeating unitsare --R'-- units of the structure ##STR251## and from 100 to 250 per 100glycol derived repeating units are hydroxy-acid derived --R"-- units.108. The polyester of claim 107 wherein, from 50 to 65 per 100 diacidderived repeating units are --R'-- units of the structure ##STR252##from 35 to 50 per 100 diacid derived repeating units are --R'-- units ofthe structure ##STR253## and from 100 to 200 per 100 glycol derivedrepeating units are hydroxy-acid derived --R"-- units of the structure##STR254##